URI scheme in email

[rdallman]

This is really simple we just need to do it. just need to define something like:

wookie://MYSTUDENTID@MYCLASSID

just something we can parse easily in the android client and include in the email for students to be able to add a class with one click instead of typing in a bunch of random chars.

[rdallman]

On that note, using HTML in the email itself has benefits. could make it real purrty. nothing like those awful image-only ones but a little markup never hurt anyone.